REVENUES

12 Months Ended

Dec. 31, 2022

Revenue from Contract with Customer [Abstract]

REVENUES

REVENUES

The Company generates revenues through the following operating segments: Environmental Services and Safety-Kleen Sustainability Solutions. The Company's Environmental Services operating segment generally has four sources of revenue and the Safety-Kleen Sustainability Solutions operating segment has two sources of revenue. The Company disaggregates third-party revenues by geographic location and source of revenue as management believes these categories depict how revenue and cash flows are affected by economic factors. The Company's significant sources of revenue include:

Technical Services—Technical Services contribute to the revenues of the Environmental Services operating segment. Revenues for these services are generated from fees charged for waste material management and disposal services including onsite environmental management services, large remediation projects, collection and transportation, packaging, recycling, treatment and disposal of waste. Revenue is primarily generated by short-term projects, most of which are governed by master service agreements that are long-term in nature. These master service agreements are typically entered into with the Company's larger customers and outline the pricing and legal frameworks for such arrangements. Services are provided based on purchase orders or agreements with the customer and include prices based upon units of volume of waste, material and personnel costs as well as transportation and other fees. Collection and transportation revenues are recognized over time, as the customer receives and consumes the benefits of the services as they are being performed and the Company has a right to payment for performance completed to date. The Company uses the input method to recognize revenue over time, based on time and materials incurred as a basis for measuring the satisfaction of the performance obligation. Revenues for treatment and disposal of waste are recognized upon completion of treatment, final disposition in a landfill or incinerator, or when the waste is shipped to a third-party for processing and disposal. The Company periodically enters into bundled arrangements for the collection and transportation and disposal of waste. For such arrangements, transportation and disposal are considered distinct performance obligations and the Company allocates revenue to each based on the relative standalone selling price (i.e., the estimated price that a customer would pay for the services on a standalone basis). Revenues and the related costs from waste that is not yet completely processed and disposed of are deferred. The deferred revenues and costs are recognized when the services are completed. The period between collection and transportation and the final processing and disposal ranges depending on the location of the customer, but generally is measured in days.

Industrial Services and Other—Industrial Services contribute to the revenues of the Environmental Services operating segment. These revenues are primarily generated from industrial and specialty services provided to refineries, mines, upgraders, chemical plants, pulp and paper mills, manufacturing facilities, power generation facilities and other industrial customers throughout North America. Services include in-plant cleaning and maintenance services, plant outage and turnaround services,

specialty cleaning services including chemical cleaning, pigging and high and ultra-high pressure water cleaning, leak detection and repair, daylighting, production services and upstream energy services. Services are provided based on purchase orders or agreements with the customer and include prices based upon daily, hourly or job rates for equipment, materials and personnel. The Company recognizes revenue for these services over time, as the customer receives and consumes the benefits of the services as they are being performed and the Company has a right to payment for performance completed to date. The Company uses the input method to recognize revenue over time, based on time and materials incurred.

Field and Emergency Response Services—Field and Emergency Response Services contribute to the revenues of the Environmental Services operating segment. Field Services revenues are generated from cleanup services at customer sites, including those managed by municipalities and utility providers, or other locations on a scheduled or emergency response basis. Services include confined space entry for tank cleaning, site decontamination, remediation, railcar cleaning, manhole/vault clean outs, product recovery and transfer and vacuum services. Additional services include filtration and water treatment services. Response services for environmental emergencies of any scale range from man-made disasters such as oil spills to natural disasters such as hurricanes. Emergency response services also include spill cleanup on land and water, as well as contagion disinfection, decontamination and disposal services. Field and emergency response services are provided based on purchase orders or agreements with customers and include prices generally based upon daily, hourly or job rates for equipment, materials and personnel. The Company recognizes revenue for these services over time, as the customer receives and consumes the benefits of the services as they are being performed and the Company has a right to payment for performance completed to date. The Company uses the input method to recognize revenue over time, based on time and materials incurred. The duration of such services can be over a number of hours, several days or even months for larger scale projects.

Safety-Kleen Environmental Services—Safety-Kleen Environmental Services revenues contribute both to the Environmental Services operating segment and the Safety-Kleen Sustainability Solutions operating segment depending upon the nature of such revenues and operating responsibilities relative to executing the revenue contracts. Revenues from providing containerized waste handling and disposal services, parts washer services and vacuum services, referred to collectively as the Safety-Kleen branches' core service offerings, contribute to the revenues of the Environmental Services operating segment. In addition, sales of packaged blended oil products and other complementary product sales contribute to the revenues of the Environmental Services operating segment. Revenues generated from waste oil, anti-freeze and oil filter collection services, sales of bulk blended oil products and sales of bulk automotive fluids contribute to the Safety-Kleen Sustainability Solutions operating segment.

Generally, the revenue from services is recognized over time, as the customer receives and consumes the benefits of the services as they are being performed and the Company has a right to payment for performance completed to date. The duration of such services can be over a number of hours or several days. The Company uses the input method to recognize revenue over time, based on time and materials incurred. Product revenue is recognized upon the transfer of control whereby control transfers when the products are delivered to the customer. Containerized waste services consist of profiling, collecting, transporting and recycling or disposing of a wide variety of waste. Related collection and transportation revenues are recognized over time, as the customer receives and consumes the benefits of the services as they are being performed and the Company has a right to payment for performance completed to date. Parts washer services include customer use of the Company's parts washer equipment, cleaning and maintenance of the parts washer equipment and removal and replacement of used cleaning fluids. Parts washer services are considered a single performance obligation due to the highly integrated and interdependent nature of the arrangement. Revenue from parts washer services is recognized over the service interval as the customer receives the benefit of the services.

Safety-Kleen Oil—Safety-Kleen Oil related sales contribute to the revenues of the Safety-Kleen Sustainability Solutions segment. These revenues are generated from sales of high-quality base and blended lubricating oils to third-party distributors, government agencies, fleets, railroads and industrial customers. The business also sells recycled fuel oil to asphalt plants, industrial plants and pulp and paper companies. The used oil is also processed into vacuum gas oil which can be further re-refined into lubricant base oils or sold directly into the marine diesel oil fuel market. Revenue for oil products is recognized at a point in time, upon the transfer of control. Control transfers when the products are delivered to the customer.

The following tables present the Company's third-party revenue disaggregated by source of revenue and geography (in thousands):

	For the year ended December 31, 2022
	Environmental Services		Safety-Kleen Sustainability Solutions		Corporate		Total
Primary Geographical Markets
United States	$	3,675,880	$	899,780	$	507	$	4,576,167
Canada	469,093		121,345		—		590,438
Total third-party revenues	$	4,144,973	$	1,021,125	$	507	$	5,166,605
Sources of Revenue
Technical Services	$	1,495,264	$	—	$	—	$	1,495,264
Industrial Services and Other	1,311,072		—		507		1,311,579
Field and Emergency Response Services	575,300		—		—		575,300
Safety-Kleen Environmental Services	763,337		199,360		—		962,697
Safety-Kleen Oil	—		821,765		—		821,765
Total third-party revenues	$	4,144,973	$	1,021,125	$	507	$	5,166,605

	For the year ended December 31, 2021
	Environmental Services		Safety-Kleen Sustainability Solutions		Corporate		Total
Primary Geographical Markets
United States	$	2,631,112	$	693,542	$	299	$	3,324,953
Canada	394,795		85,818		—		480,613
Total third-party revenues	$	3,025,907	$	779,360	$	299	$	3,805,566
Sources of Revenue
Technical Services	$	1,209,624	$	—	$	—	$	1,209,624
Industrial Services and Other	705,999		—		299		706,298
Field and Emergency Response Services	466,380		—		—		466,380
Safety-Kleen Environmental Services	643,904		161,587		—		805,491
Safety-Kleen Oil	—		617,773		—		617,773
Total third-party revenues	$	3,025,907	$	779,360	$	299	$	3,805,566

	For the year ended December 31, 2020
	Environmental Services		Safety-Kleen Sustainability Solutions		Corporate		Total
Primary Geographical Markets
United States	$	2,287,796	$	452,435	$	(674)	$	2,739,557
Canada	349,845		53,731		964		404,540
Total third-party revenues	$	2,637,641	$	506,166	$	290	$	3,144,097
Sources of Revenue
Technical Services	$	1,062,714	$	—	$	—	$	1,062,714
Industrial Services and Other	480,331		—		290		480,621
Field and Emergency Response Services	461,036		—		—		461,036
Safety-Kleen Environmental Services	633,560		175,676		—		809,236
Safety-Kleen Oil	—		330,490		—		330,490
Total third-party revenues	$	2,637,641	$	506,166	$	290	$	3,144,097

Contract Balances

(in thousands)	December 31, 2022		December 31, 2021
Receivables	$	964,603	$	792,734
Contract assets (unbilled receivables)	107,010		94,963
Contract liabilities (deferred revenue)	94,094		83,749

The timing of revenue recognition, billings and cash collections results in billed accounts receivable, unbilled receivables (contract assets) and customer advances and deposits or deferred revenue (contract liabilities) on the consolidated balance sheet. Generally, billing occurs subsequent to revenue recognition, as a right to payment is not just subject to passage of time, resulting in contract assets. Contract assets are generally classified as current. The Company sometimes receives advances or deposits from its customers before revenue is recognized, resulting in contract liabilities. These assets and liabilities are reported on the consolidated balance sheet on a contract-by-contract basis at the end of each reporting period. The contract liability balances at the beginning of each period presented were generally fully recognized in the subsequent three-month period.

Variable Consideration

The nature of the Company's contracts give rise to certain types of variable consideration, including in limited cases volume discounts. Accordingly, management establishes a revenue allowance to cover the estimated amounts of revenue that may need to be credited to customers' accounts in future periods. The Company estimates the amount of variable consideration to include in the estimated transaction price based on historical experience, anticipated performance and management's best judgment at the time and to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved. There have been no material changes in estimates of variable consideration in the periods presented.

Contract Costs

Contract costs include direct and incremental costs to obtain or fulfill a contract. Parts washer costs include costs of solvent, commissions paid relating to revenue generated from parts washer services, and transportation costs associated with transferring the product picked up from the services as it is returned to the Company’s facilities or a third-party site. Costs related to the treatment of waste include costs for waste receiving, drum movement and storage, waste consolidation and transportation between facilities.

The Company’s contract costs that are subject to capitalization are comprised of costs associated with parts washer services and costs associated with the treatment and disposal of waste. As of December 31, 2022 and 2021, the Company's deferred contract costs totaled $29.7 million and $26.4 million, respectively. Deferred parts washer costs are recognized over the service interval as the customer receives the benefit of the services, and deferred costs related to treatment and disposal of waste are recognized when the corresponding waste is disposed. Deferred costs are included within total current assets in the

Company’s consolidated balance sheets. The deferred contract cost balances at the beginning of each period presented were fully recognized in cost of revenue in the subsequent three-month period.